The icons are the same clickable icons found when you’re browsing maps of areas and are visible by default. When clicked, the icons pop open a little info-bubble that’s familiar as the same info-bubble boxes which appear over the standard maps view for place marks.

I’ve referred to these icons before as “landmark icons“, and these are generally going to be advantageous for businesses which have them, since they enable people browsing areas via Street View to discover them — yet another potential means of promotion.